28i Worcester pressure was zero on grey arrow so

[pinklady54]

last week pressure was zero so opened up the taps on pipe underneath waited till it got to 1.5 bars turned off both.
worked fine now not working again is there another common fault to this boiler? please
is it pressure relief valve?
or what thanks,
from a capable woman who can do....

 

[linkyplumb]

Check that the prv is not leaking.

Is it happening overnight or over a few days?If overnight or in a short space of time then;

Another way of deciding if it is boiler prob or system prob is to pressurise to 1.5bar.Isolate flow and return valves under boiler(far right and far left).
If pressure still drops its boiler side, if not then system side.

Hope this helps

Graham